Never Alone Again
by crazyhpgirl
Summary: What if the world of Harry Potter was just another parallel of The Doctor's world? What would happen if the TARDIS decided to take The Doctor and his companions there? There, they meet a remarkable young lady that will change their lives forever. AU of Season 5 with Ten, Rose, and Jack. Rated M for language, violence, and adult themes in later chapters.
1. Prologue

**Disclaimer: I definitely don't Doctor Who or Harry Potter. If I did, I don't think I would be writing for free.**

**Prologue**

TARA was exhausted. She had been up for almost forty-eight hours working on a new potion. It was fiddly as hell and required constant attention. She had just finished it minutes before, another potion that would change the world. That's what Tara did. She was a Potions expert and Surgical Healer for the Dublin branch of St. Mungo's Hospital for Magical Maladies and Injuries.

The potion she had just finished would be used to immunize people against the bite of vampires. She admitted to herself that this was one of her more brilliant pieces of work. Not quite as brilliant, though, as her achievement two months ago. That was when she had discovered a cure for lycanthropy. Her recent successes managed to get her permanent resident status and a huge estate in Roscommon. Ever the workaholic, she turned part of her home into a top-notch research facility.

Tara snapped out of her musings and found that she had wandered into her media room. She had intended to go straight to bed, but this was even better. Yes, she was tired, but she was also rather wound up from drinking too much coffee. Perhaps a couple episodes of Doctor Who would help her to unwind. She quickly found her favorite season two episode and settled into her comfy chair. She soon fell asleep to the sound of The Doctor's voice.

MEANWHILE ON THE TARDIS….

The Doctor was frantic. Alarms were blaring, the ship was shaking, and the TARDIS was out of control. Rose was on the floor, trying to get to one of the battered jump seats. Jack was hanging onto one of the coral struts for dear life. As for The Doctor, the TARDIS was doing her best to keep him away from the console. There was something she needed to show him, and she didn't want him interfering with the controls.

The Doctor tried reaching for the stabiliser one more time. "Come on old girl! You're going to smash us all to pieces!" Another violent shake sent Rose flying into the Time Lord. The Doctor couldn't help but smile at his pink and yellow (and now black and blue) human. "Well, hello. Fancy running into you here!"

Rose grinned back, despite the situation at hand. "Hello yourself, Doctor." She noticed that he hadn't tried to move her off of him yet. Unfortunately, Jack picked that exact moment to point out that they had landed.

Jack helped Rose up, and The Doctor sprang to his feet. Cautiously, he made his way to the door, Rose and Jack following close behind. He opened the door, not knowing what he would find. They expected maybe Cybermen, Daleks, or alien soldiers. They didn't, however, expect a shocked young woman pointing a polished stick at them. The last thing they remembered was red beam of light headed straight for them.


	2. Chapter 1

**Disclaimer: Nope. Still don't own Doctor Who or Harry Potter. My bank account wishes that I did.**

**AN: For those who may be wondering how Jack and Rose wound up traveling with The Doctor again, don't worry. It will all be explained in a few chapters. Most likely, chapter 4 or 5.**

CHAPTER ONE

Tara awoke to a strange but familiar sound. She checked the television, but it was turned off. The sound grew louder, and the air felt charged with electricity. Whipping her wand out, Tara turned around to face the strangest thing she ever seen. There, in her media room, stood a large blue police box.

The door opened, revealing three people that she never thought she would see. Acting reflexively, she let loose three quick stunning spells. She levitated the three intruders to the couch and bound them to it. She gathered her wits as best she could and woke them up.

Within milliseconds, the room filled with cries of indignation. Tara quickly cast a silencing charm on the shocked "guests." She really wanted to avoid bringing the two security elves into this. After taking a deep breath, she addressed the people on her couch. "I'll remove the silencing charm if the three of you swear to not shout. I really don't want to have to set my guards on you."

The blonde woman in the middle nudged her two male companions and nodded her agreement. The men followed her example immediately. Tara considered them warily before waving her wand them, returning their ability to speak.

Glaring at them, she asked, "Who are you and how did you get past my anti-apparition wards?"

The man in the suit looked at her appraisingly before replying. "I'm The Doctor. The lovely woman beside me is Rose Tyler. And the man next to her is…" The Doctor was interrupted by the very man he was trying to introduce.

"Captain Jack Harkness," he said. "And who are you, Gorgeous?"

The woman call Rose shook her head exasperatedly. "Jack, do you EVER stop flirting? We're all bound to a sofa in a mysterious house. Now is NOT the time."

Tara, taken aback by Jack's flirting for a moment, snapped to her senses. "It really isn't much business of yours what my name is, but since I'm a gracious captor, I'll tell you. My name is Tara Jones. As for you three, well I really don't believe you. The names you gave me are from my favorite television show. You are obviously spies or hit men that have taken on the appearance of three characters from said show."

"The Doctor" stared hard at her, consternation clearly written on his face. "We're not lying, and we certainly aren't spies or hit men. Our ship went a bit rogue and landed us here. I assure you, I am not imitation some character from the telly."

Tara stooped down so that her face was mere inches from his. "I wasn't born yesterday, pal. I'm quite used to having my life threatened and am will equipped to handle people like you." With that said she flicked her wand at the telly and brought up a scene from Doctor Who. This particular scene showed Rose, The Doctor, and Jack confronting Davros and his Daleks.

The three captives gasped at seeing their faces on Netflix of all things. Tara turned the TV off and faced them, anger radiating from her like heat from the sun. "Those people are three of my favorite actors. I demand you tell me who you really are before I call in the Aurors. Harry Potter is one of my closest friends, and as Head Auror, he is authorized to send you straight to Azkaban. So what will it be? The truth or prison?"

At the mention of Harry Potter, The Doctor paled considerably. "No!" he exclaimed in a raspy voice. "No! Can't be! Oh, that brilliant ship of mine! She's gone and landed us on another parallel world! One that has worked its way into the mind of JK Rowling! She must have thought that the visions were just dreams that would make an excellent story. Oh that is fantastic!"

Tara gaped at The Doctor. Parallel worlds? She had been researching those for weeks! Could these people really be who they say they are? After picking her jaw up off of the floor, Tara addressed the possible dimension hoppers. "I've decided to reconsider. If you are all telling the truth, then you won't mind taking a truth potion." With that said, she magically produced three capsules filled with a clear liquid. "You can trust that these are not poison. I am a healer, dedicated to help, not harm." She flicked her wand to free their hands. She then gathered four bottles of water from the mini fridge, handing one to each prisoner and keeping on for herself. As a gesture of goodwill, she also conjured a truth serum capsule for her to take, as well. She then moved a chair to face the couch and sat down. "As you can see, I have decided to take the serum with you. That way we can all trust one another to be honest."

At this, The Doctor fidgeted a bit. "Weeelll, I guess I best start the honesty thing with a little admission. That truth serum probably won't work on me. Superior Time Lord biology and all that."

Tara smirked at him. "You underestimate my potion making ability, sir. This potion has been tested on many people, all with varying degrees of magical ability, physical strength, and health. It may not last as long with your 'superior biology,' but it WILL work." She then raised the capsule to her mouth. "Shall we?" In unison, the four of them took the pills.

The results were nearly instantaneous. All of them relaxed into their seats and smiled, even the supposedly superior Doctor. Tara leaned forward and started the questioning. "Well then, my dears. I'd like each of you, in turn, to tell me your name and where you are from. Let's start with Handsome over there in the suspenders."

The Captain flashed her a brilliant smile. "Like I said before, Gorgeous, I'm Captain Jack Harkness. I'm a former 51st century Time Agent from the Boeshane Peninsula. I recently left Torchwood to travel with these two. I'm very much hoping you join us." He winked at her as he finished that last sentence.

The young blonde rolled her eyes before taking her turn. "I'm Rose Marion Tyler. I'm originally from London, Lived in a parallel version of it for a while before I used a dimension cannon to get back to The Doctor. Been with 'im ever since." She smiled at The Doctor, love shining in her eyes.

The Doctor sighed, giving in to the potion. "Well, Tara, seems like you really are an expert potioneer. I'm The Doctor, tenth one. I'm from the planet known as Galifrey. It was destroyed in the last Time War. I had to destroy it to end the War. That blue box behind me is my ship. She's a TARDIS, that's Time And Relative Dimension In Space. She's a lot bigger on the inside despite her outer size. She used a lot of energy to get us here. For some reason, she WANTED us to meet you." He clammed up and waited for Tara to tell him why she would be remarkable enough to attract the attention of his sentient ship.

Tara took a moment to absorb all of the information she had received thus far. After considering their stories, she released their bonds and began telling them about herself. "My name is Tara Jones. I found out that I was a witch on my seventeenth birthday. My parents kept my powers a secret from me. But as soon as I turned seventeen, I got a letter explaining everything. I was furious and decided to properly educate myself. I secretly took correspondence courses, and professors came at night to tutor me. I managed to finish in just less than a year.

"Two years ago, St. Mungo's asked me to help pilot the new surgical healing program. They put me in an accelerated surgical program that I completed in six months. Now I am a surgical healer and researcher for the Dublin branch. Though some of my research has the potential to change the world, I can't imagine that it would cause the TARDIS to jump dimensions."

The Doctor's eyes grew wide at the mention of changing the world. Before he could stop himself, he asked, "Change the world how? I'm hoping it's something good, because I like you, and I don't want to have to fight you."

Jack glared at The Doctor. "How could you even think that this lovely woman would intentionally cause harm? I'm very good at reading people, and I can sense nothing but good from her. Besides, do you really think the TARDIS would park us right in front someone intent on destroying?" Tara blushed as the Captain defended her honor. Jack caught this and winked at her.

The Doctor was still obviously not convinced. He continued to scowl until Rose placed a placating hand on his knee. This simple gesture had an instant effect in calming him. After a moment, he looked up at Tara. "Alright. Just remember that I don't give second chances."


	3. Chapter 2

**Disclaimer: Don't own Doctor Who or Harry Potter, unfortunately.**

**A/N: 67 views in 2 days! You guys are awesome!**

CHAPTER TWO

Nine am found the four of them gathered in the kitchen. Tara laid out a big breakfast of pancakes, eggs, bacon, toast, fruit, and tea. They ate in silence for a few minutes before The Doctor spoke. "Okay, Tara. I think it's time to figure out why the TARDIS brought us here." He pointed his unpeeled banana at her. "You have obviously done something extremely important, and I want to know what it is. As far as I can tell, you're just an average human that happens to be able to use magic. Nothing special."

Tara cocked an eyebrow at him. Rude and not ginger. "And who are you to be the judge of that? I don't normally like to talk about my achievements, but I'll make an exception for you. In the Muggle world, I was just a below average student. Barely managed to graduate from high school. But I excelled in my magical education. I went through seven years' worth of Hogwarts curriculum in less than a year. My strongest areas were Charms, Transfiguration, and Potions. I originally planned on entering the Healer's Academy after I finished, but my parents intervened.

"I wasn't home when my acceptance letter arrived, but my parents were. I had never seen them so angry. They threatened to put me out and disown me completely. They were even going to tell everyone that I had died. I had no choice but to put aside magic and just live like a Muggle. I even met someone. We fell in love and got married a year later. Things never felt quite right, though. He got abusive, eventually. One day, we had an argument, and he slapped me. I kicked him out that same day. We were living with my parents at the time, so I at least had a roof over my head." Tara paused a moment, letting the memories wash over her.

Before she could begin again, Jack spoke up from his position beside her. "Why are you telling us this? It's obviously very painful, and it has nothing to with what's going on now. You are suffering needlessly." He put an arm around her and pulled into a hug.

Tara pulled away and gave him a weak smile. "But it has everything to do with it. My past is what led me here. So please, just let me continue." She poured herself some more tea and pressed on with her story. "It took me a year to save for the divorce. During that time, I studied healing in secret. I would lead a normal Muggle life during the day, then spend my nights studying and practicing. By the time I finally got divorced, I was a licensed healer. Not long after, I got offered a job at St. Mungo's in London. I severed ties with my family and friends and left the States. As painful as it was, I couldn't include them in my new life.

Just a few months after starting over, I got approached to do the surgical healing program. After graduating, they moved me here to help train more healers and to head a research team. Maybe that research is what brought you here." She stopped there, knowing that The Doctor was bursting with questions.

The Time Lord was practically bouncing in his seat. "So you're a genius!" he exclaimed. "Able to learn at an accelerated rate, and obviously quite powerful. But the universes are all full of geniuses. What drew the TARDIS to you? What does you research involve?"

Tara took a deep breath as she prepared to explain exactly what she did. "Suppose I should start with three and a half months ago. There had been a rash of werewolf attacks in the area, and we ended up treating many of the victims. All those poor children…" She shuddered at the memory of the crying that filled the wards. "One day, after losing a particularly sweet little girl, I decided that enough was enough. I went straight to my makeshift lab as soon as I got back to my flat. I spent countless hours and many sleepless nights surrounded by bubbling potions and stacks of parchment. It took just over a month of near continuous work, but it was worth every second. I discovered a cure for Lycanthropy. No one will ever need to suffer a werewolf transformation ever again."

She paused a moment to get control over her emotions. The Doctor took the opportunity to speak. "You cured lycanthropy? I assume that people have been trying and failing to find a cure for centuries." Tara nodded at his correct assessment. "Hundreds of years, scientists, doctors, and healers have been failing to find the cure, and you managed to do it in just over a month! No wonder the TARDIS brought us to you! What else have you done?"

The young witch smiled a bit at his rare praise. "I guess now would be a good time to tell you that I just finished an immunization against vampirism. Oh, and I also happen to be an Empath and Seer."

The Doctor's eyes were practically bugging out of his head by this point. Rose's mouth was gaping open, and Jack was staring blankly at the wall behind her. The three were obviously stunned by the proclamations of this impossible woman.

Tara waved her hand in front of Jack's face, bringing him back to reality. "Well," he said, "you are certainly a remarkable young woman. We could really use someone like you on board. If that's alright with Rose and The Doctor, of course."

Rose and Jack both gave The Doctor pleading looks. The Time Lord grinned at his companions before turning to Tara. "Weeelll, alright. What d'ya say, Tara? Care to join us? Take a couple of hours to think if you need to. This will mean leaving your universe, possibly never to return. I'll understand if you choose to stay."

Tara sat quietly for a few minutes, obviously giving serious thought to this proposal. She sighed and put down her mug of tea. "I can't just up and leave."

The travelers looked crestfallen. Rose spoke for the small group. "We understand. We were asking a lot of you. You've got a great life here. Why would you give that up?"

Tara laughed, surprising them. "you didn't let me finish. I can't leave_ yet_. I have a few things that need done first. I've got to come up with a cover story, get some money, arrange for my staff to stay employed, etcetera. I am most definitely coming with you."


End file.
